Once per turn, you can either: Target 1 face-up monster you control; equip this card to that target, OR: Unequip this card and Special Summon it in face-up Attack Position. While equipped by this effect, the equipped monster cannot be targeted or destroyed by your opponent's monster effects. (A monster can only be equipped with 1 Union Monster at a time. If the equipped monster would be destroyed by battle, destroy this card instead.)